Which method is usually used to treat plants with most of their leaf area above the water surface?

The method that is typically employed to treat plants with a majority of their leaf area above the water surface is spraying. This technique is effective because it allows for direct application of the treatment solution onto the plant's foliage, ensuring that the active ingredients can be absorbed efficiently by the leaves. When a plant's leaves are predominantly above the water, spraying enables better coverage and contact with the targeted areas, improving the likelihood of controlling the pest or managing the aquatic plant.

Spraying can also be adjusted to ensure minimal drift and effective penetration of the chemical to the desired areas of the plant, making it a versatile choice for targeting both pests and unwanted aquatic vegetation. The visibility of the target area enhances the operator's ability to apply the treatment accurately.

In contrast, other methods like drip application, granular application, and subsurface injection may not provide the same level of direct contact with the exposed foliage and can be less effective for plants that are primarily above water.